Dynamic mechanical analysis (DMA) and ultrasonic measurements were carried out to study the temperature and frequency dependences of viscoelastic properties of polyurea. Master curves of Young’s storage and loss moduli were developed from the DMA data. Relaxation spectra were subsequently calculated by means of two approximate models, and the apparent activation energy of molecular rearrangemen...

in order to investigate the combined effects of shift work and heat stress on the physiological parameters, such as heart rate (hr) and body temperature (bt), a hot-dry working environment was investigated for 53 workers in foundry workshops. in this study wet bulb globe temperature index (wbgt) was measured and along with that simultaneously heart rate and oral temperature were checked in 3 sh...

The effect of molecular weight on the viscoelastic performance of an advanced polymer (LaRC-SI) was investigated through the use of creep compliance tests. Testing consisted of short-term isothermal creep and recovery with the creep segments performed under constant load. The tests were conducted at three temperatures below the glass transition temperature of each material with different molec...

Background & Aim: Restrictions on the use of synthetic antioxidant such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are being imposed because of their carcinogecity . Experimental: In this investigation, optimization of phenolic extraction process from methanolic (80%) extract (v/v) of  Flomideschema parviflorum through response surface methodology by Fulin Ci...

Background/introduction In MRI-guided high-intensity focused ultrasound (MRHIFU) therapy, temperature-dependent proton resonance frequency (PRF) shift is a key factor to quantify and visualize the spatial heating pattern in treated and surrounding tissue. However, during treatment, multiple scanner-related changes can impact the accuracy of the temperature measurements obtained with the PRF shi...

Structural properties, energies behavior and NBO analysis was performed for1-5 prototrophic shift endinelboran where substitutions like H, CH3 and CF3 that were placed on Benzene were investigated by usingDFT-B3LYP/6-311+G** level of theory. The Results show that, -BH2 shift doesn’t take place and a kind of[1,3] shift for borotrophic occured. In prototrophic shift, however, [1,5] transition eas...

A newly isolated, temperature-sensitive mutant of a haploid strain of Saccharomyces cerevisiae is described. Its shift to nonpermissive temperature (35 C) resulted in an irreversible change to rho(-), causing, within four to six generations, more than 90% of the cells to form petite colonies. Genetic analysis revealed extrakaryotic inheritance of this temperature-sensitive mutation. Data presen...

Background & Aim: Restrictions on the use of synthetic antioxidant such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are being imposed because of their carcinogecity . Experimental: In this investigation, optimization of phenolic extraction process from methanolic (80%) extract (v/v) of  Flomideschema parviflorum through response surface methodology by Fulin Ci...

(Dated: March 13, 2002) The quality factor (Q) of a violin mode of a fiber under tension is related to the Q of the unloaded fiber by the dilution factor. We calculate this dilution factor from measurements of the Q’s and compare to measurements based on the shift of the violin mode frequencies with temperature, and to theoretical predictions. We also report supporting measurements of the tempe...